81354915 has 32 divisors (see below), whose sum is σ = 145938240. Its totient is φ = 42997248.

The previous prime is 81354913. The next prime is 81354919. The reversal of 81354915 is 51945318.

It is not a de Polignac number, because 81354915 - 2¹ = 81354913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81354915.

It is not an unprimeable number, because it can be changed into a prime (81354913) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12589 + ... + 17921.

It is an arithmetic number, because the mean of its divisors is an integer number (4560570).

Almost surely, 2^81354915 is an apocalyptic number.

81354915 is a deficient number, since it is larger than the sum of its proper divisors (64583325).

81354915 is a wasteful number, since it uses less digits than its factorization.

81354915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5460 (or 5454 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 81354915 is about 9019.6959483122. The cubic root of 81354915 is about 433.3058960274.

The spelling of 81354915 in words is "eighty-one million, three hundred fifty-four thousand, nine hundred fifteen".